A prime symptom of cancer is the loss of body weight, which often occurs with no noticeable change in food intake. Our past studies show that the nutritional needs of a growing tumor take priority over the nutritional needs of the host as measured by a decreased cell proliferation activity in some of the host tissues and by the wasting of the carcass mass. Since tumors depend largely on glycolysis for energy, we have decided to find out how the metabolism of the host might change in the face of the ever increasing demands for glucose by the growing tumor. Our protocol calls for giving total parenteral feeding of a defined diet to rats with and to rats without a transplantable tumor where only the level of glucose intake is varied. Measurements will be made on a number of tumor and host parameters to assess the wasting of the tissues and the carcass, growth of the tumor and the contribution of gluconeogenesis to the maintenance of normoglycemia. This study should help show that a growing tumor can force the host to meet its ever increasing nutrient needs by alterations of the host's ability to produce supplies for the tumor. The long-term objective is to gain enough information in this area to design therapy which may be used to prevent cancer cachexia and which would therefore be a desirable adjunct permitting a more effective cancer therapy.